Approach for airborne radar ISAR imaging of ship target

Ship target ISAR imaging has significant meaning in maritime surveillance and traffic management in vast sea areas. This paper propose a novel approach for long observation time of ship target from airborne radar. First, a second-order generalised keystone formatting method is used to compensate for the range curvature induced by long integration time. Secondly, estimate the target motion parameter by virtue of time frequency techinque(WVD) and reomve the quadratic term of slow time, then use the second- order keystone formatting again to eliminate the residual range walk. So the coupling of the range and azimuth term are completely removed. At last, the clear ISAR image can be obtained. Both numerical and experimental results are provided to demonstrate the performance of the proposed method.